Injector for gas compression



NOV. 8, 1960 DIEL 2,959,345

INJECTOR FOR GAS COMPRESSION Filed Aug. 14, 1957 INVENTOR. A L 0 Y6 D /L AT ToRNEy5 "any United States Patent INJECTOR FOR GAS COMPRESSION Aloys Diel, Kreis Huenfeld, Reckrod, Germany Filed Aug. 14, 1957, Ser. No. 678,086

2 Claims. (Cl. 230-95) The present invention relates to an injector for gas compression operated more particularly with high temperature propellants.

It is known that upon compression of gases in an injector, superheating takes place and that, as a consequence, a higher input of energy is necessary. It has therefore been attempted to reduce the temperature increase in compression by injecting water, which evaporates when superheating of the propellant in the injector sets in; a temperature increase was thereby avoided to a considerable extent. However, the steam generated 'when water evaporates has to be condensed when compression in the injector takes place. Whereas the energy necessary for compression is decreased, because the compression occurs without superheating, the advantage thus obtained is ofi-set by the fact that the newly formed steam has to be compressed, so that the injection of water is no considerable improvement.

Similar conditions prevail when, for instance, steam injectors are operated with a highly heated propellant, particularly with superheated steam, which is available in most cases. The energy which can be put to work is much higher per kilogram superheated steam than for saturated steam, but it does not become efiective since the temperature range in which compression occurs is considerably higher than with saturated steam; therefore, more compression work has to be done, so that the advantage originally present in the use of superheated steam is lost.

In the following this will be more fully explained by an example.

When steam is used as propellant with a pressure of one atmosphere absolute, 23 calories are needed for the compression of steam of 30 mm. Mg. to 60 mm. Mg. per one kilogram aspirated steam, whereas the energy available is 87 calories per one kilogram of propellent steam. The temperature of the mixture lies at about 60 C. and the efi'iciency can be expressed by the ratio 23/ 87=26.4%. When steam of one atmosphere absolute and 300 C. is used, upon expansion of this steam 118 calories are set free, so that for the compression 26.4% 118=31.2 calories are available. The temperature of the mixture now lies at 160 C., so that for the compression 29 calories are necessary. For each kilogram propellent steam 31.2/29=1.07 kilograms steam can be compressed, that is to say 7% more than upon use of saturated steam.

If, however, steam of 300 C. and one atmosphere absolute were used for compression without injection of water, whereby a mixing temperature of 60 C. would be obtained, it would be possible to compress with one kilogram propellent steam 3l.2/23=1.35 steam. This is an improvement by 25%.

In injectors of this type it has been proposed to cool the difiuser, either by providing it with cooling ribs, or by providing a cooling jacket for the passage of a cool- 2,959,345 7 PatentedvNow-e,196i) 2 ing agent. However, 1 a satisfactory coolinghas-not been obtained'byth'ese arrangements.

Accordingto theprese'nt invention the hitherto prevailing disadvantages have been overcome and suliicient cooling is provided, so that the injector will have the desired efficiency.

According to the invention, the diffuser is provided with a jacket for the passage of a coolant, and is furthermore provided with cooling ribs, which are so designed that they extend into the injector or that they pass right through the same. According to an advantageous embodiment channels are provided for the passage of coolant between the cooling ribs arranged inside the difluser.

Apart from the eflicient cooling accomplished by the subdivision of the current of steam it is a further advantage due to the arrangement of the ribs in the interior that eddy formation is avoided, so that the compression can be efiected with a lower energy input.

The invention will now be more fully described with reference to the accompanying drawing but it should be understood that this is given by way of illustration and not of limitation and that many changes in the details can be made without departing from the spirit of the invention.

In the drawing:

Fig. 1 is a diagrammatic showing of the injector in longitudinal section;

Fig. 2 is a transverse section through the diffuser with cooling jacket, and

Fig. 3 is a transverse section of a diflerent embodiment of the difliuser.

The injector comprises a so-called suction head 1, and a diffuser 2. Within the head, an admission pipe 3 for the propellant is arranged which passes the propellant to a nozzle 4. Compression sets in, as known, in the converging part of the difluser 2, and continues in the diverging part 2a. The diifuser is provided with a jacket 5 through which, e.g. cold water as a coolant is admitted at 6 and is withdrawn at 7.

Within the cooling jacket 5, ribs are disposed on the difiuser as shown in Fig. 2 at 8; these ribs promote the cooling action, since they extend into the interior of the diffuser, so that the steam, in passing, not only transmits heat to the diffuser wall, but also directly to the ribs.

According to another embodiment, shown in Fig. 3, in order to increase the cooling action, the ribs may be in the form of continuous cooling faces. As shown in that figure, several parallel surfaces 9, 10, 11 are provided, which form together with the diffuser wall passages to be traversed by the cooling agent. 8a are additional cooling ribs, which may be disposed inside or outside the diffuser.

The cooling ribs and the cooling faces may have diffent shapes from the ones shown in the drawing.

What I claim is:

1. An injector for gas compression operated with high- 1y heated propellants, which comprises a suction head, a diifuser integrally connected to said suction head, an admission pipe disposed in said suction head and extending into said diffuser, a nozzle forming the terminal part of said admission pipe in said difluser, and means for cooling said diffuser, said means comprising a cooling jacket disposed around said difiuser and cooling ribs disposed within said cooling jacket and extending into the interior of said difiuser.

an admission pipe disposed in said suction head and extending into said diifuser, a nozzle forming the terminal part of said admission pipe in said diffuser, and means for cooling said difluser, said means comprising a coolingjacket disposed around said diffuser and cooling ribs connected to said cooling jacket and extending through the interior of the converging and diverging parts of said difiuser.

References Cited in the file of this patent FOREIGN PATENTS Austria Jan. 10, 1908 

